TSUKUBA — Radioactive leaks, such as at the Fukushima Daiichi nuclear plant, contaminate the local environment. Contamination of soil and water by the radioactive form of cesium is a major problem, since it persists for a long time; levels of radioactivity reduce by half only every 30 years. Effective detection and removal of radiocesium would accelerate recovery of the environment.

Current detection methods can only localise contamination on a scale of meters to kilometers, and they do not specifically identify cesium. Researchers in Japan, led by Katsuhiko Ariga at the National Institute for Materials Science, have now developed a way to detect cesium contamination on a scale of millimeters. The work, published in Science and Technology of Advanced Materials, used a fluorescent molecule that labels cesium so that it can be seen with the naked eye under UV light. [link to www.japantoday.com] .